Dark field inspection includes illuminating a sample and collecting scattered radiation while bright field inspection includes illuminating a sample and collecting reflected radiation.
These different inspection techniques may provide different information about different types of defects.
Different variations of dark field inspection and bright field inspection may involve illuminating the sample at different angles—also to provide different information about different types of defects.
Using totally different dark field optics and bright field optics may be too costly and complex.
There is a growing need to provide a system that may be cost effective, and may apply various variations of both dark field inspection and bright field inspection.